JPH051710Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial field of application) This invention relates to improvements in steering dampers for motorcycles, etc.

(Prior Art) For example, in the case of a two-wheeled vehicle, steering dampers such as those shown in FIGS. 2 and 3 are used as steering dampers that absorb vibrations transmitted from the front wheels to the steering wheel. In this case, the damper 1 is interposed between the vehicle body frame 5 and an upper bracket 4 that supports the front fork 2 and the handle shaft 3.

A piston 7 is slidably housed in the cylinder 6, and oil chambers A and B are formed on both sides of the piston 7.
A piston rod 8 connected to the piston 7 is slidably supported via bearings 9 and 10 at both ends of the cylinder 6, one end of which is connected to the upper bracket 4 via an eye bracket 11, and the cylinder 6 is connected to a pillow 12 (bearing). are respectively connected to the vehicle body frame 5 via.

The piston 7 is provided with a passage 13 that communicates the oil chambers A and B, and a part of the passage 13 is provided with an orifice 14.
The oil passing through the passage 14 is squeezed to provide resistance and generate damping force.

(Problem that the invention aims to solve) By the way, in such a steering damper, the piston rod 8 is placed on both sides of the cylinder 6 due to the pressure receiving area etc. so that there is no difference in the damping force between the expansion and compression strokes. A protruding or double rod type is used, in which case the cylinder 6 is aligned with the axis l.
It must be installed a certain distance e away from the piston rod, that is, at an offset position, and as a bending moment is constantly acting on the piston rod 8, friction increases (this is caused by buckling of the piston rod 8 due to overload or during both extension strokes). This causes a large difference in the damping force of the cylinder 6), and the piston rod 8 protruding from both sides of the cylinder 6 requires a large mounting base in the longitudinal direction.

Furthermore, such steering dampers are assembled in oil to prevent air from entering the cylinder 6 when filling with hydraulic oil; Moreover, it took a long time to remove the oil adhering to the outer periphery of the cylinder 6, and the workers were also very dirty.

This idea solves these problems by
Adopts a single-rod type in which the piston rod protrudes only from one side of the cylinder, and is configured so that there is no difference in damping force during both extension strokes, and efficiently fills hydraulic oil without assembling in oil. The purpose of this study is to propose a steering damper that enables the following.

(Means for solving the problem) This idea is used, for example, in steering dampers for motorcycles, etc., in which a piston is slidably housed in a cylinder, oil chambers are defined on both sides of the piston, and the piston is made of a hollow pipe. The piston rod is slidably supported at one end of the cylinder, and the oil chambers on both sides of the piston are connected via a check valve that prevents the backflow of hydraulic oil from the oil chamber on the piston rod side to the oil chamber on the opposite side.
An oil sump chamber is provided on the outer periphery of the cylinder to compensate for fluctuations in oil volume due to changes in the piston rod's intrusion volume, and the hydraulic oil flowing into the oil sump chamber is throttled into a passage that communicates this oil sump chamber with the oil chamber on the piston rod side. A damping force generating means that provides resistance and generates a damping force is installed, and a check valve that prevents the backflow of hydraulic oil to the oil reservoir chamber is installed in a passage communicating between the oil reservoir chamber and the oil chamber on the opposite side. A lubrication valve for filling hydraulic oil is connected to the protruding end of the piston rod through a hollow part to the oil chamber on the opposite side.
Similarly, an air bleed valve is provided on the bottom wall of the cylinder that communicates with the oil sump chamber.

(Function) During both extension strokes, the hydraulic oil in the cylinder is always regulated by the check valve to flow in one direction through the damping valve and into the oil reservoir chamber, and this flow of hydraulic oil is restricted to provide resistance and damping force. generate. in this case,
The pressure-receiving area of the piston is almost equal in both expansion strokes,
Furthermore, since the oil reservoir chamber compensates for variations in the amount of oil in the cylinder due to changes in the volume entered by the piston rod, there is no large difference in damping force between the two expansion strokes.

By the way, this steering damper is a single-rod type in which the piston rod protrudes only on one side of the cylinder, so it is possible to position the cylinder on the axis and install it in a state where almost no bending moment is applied to the piston rod, etc. Due to the reduced longitudinal dimension, less installation space is required.

In addition, when filling this damper with hydraulic oil, open the oil filling valve and air bleed valve and feed the hydraulic oil from the oil filling valve through the hollow part of the piston rod, while periodically causing the piston to expand. , oil is forcibly delivered from the oil chamber on the opposite side of the piston rod to the oil chamber on the piston rod side and then to the oil reservoir chamber. Once the oil has spread over almost the entire damper and oil is coming out of the air bleed valve, open the air bleed valve when the piston is operating on the compression side and close it when the piston is on the rebound side. Just keep feeding the hydraulic oil until the oil that comes out is no longer white and cloudy (the oil no longer contains air). Note that the oil filling valve and air bleed valve shall be closed after filling with hydraulic oil is completed.

(Example) In Fig. 1, 30 is a cylinder with a bottom;
A piston 1 is slidably housed in a cylinder 30 and defines oil chambers A and B. A piston rod 32 (made of a hollow pipe) connected to the piston 31 with a rod 50 is located on one side of the cylinder 30. It is slidably supported via a bearing 33. The piston 31 is provided with a passage 34 that communicates the oil chambers A and B, and a check valve 35 is provided in the passage 34 to prevent the backflow of hydraulic oil from the oil chamber A on the piston rod 32 side to the oil chamber B on the opposite side. to wear

By defining a concave space between a flange 36 and a guide 37 (described later) on the outer periphery of the cylinder 30 with an outer shell 38 made of an elastic material such as rubber,
An oil sump chamber C is formed to compensate for changes in the amount of oil in the cylinder 30 due to changes in the volume entered by the piston rod 32.

Then, the oil chamber B on the opposite side from the piston rod 32
is communicated with the oil reservoir chamber C via a passage 40 formed in the cylinder bottom wall 50, and a check valve 39 for preventing backflow of hydraulic oil to the oil reservoir chamber C is interposed in this passage 40. Further, a passage 41 is provided that communicates the oil reservoir chamber C with the oil chamber A on the piston rod 32 side, and a part of the passage 41 is connected to a case 42 that houses the bearing 33 and a guide 37 that screws and supports the case 42 so as to be movable in the axial direction. A damping valve 43 is installed in this passage 41 portion to throttle the hydraulic oil flowing into the oil reservoir chamber C to provide resistance and generate a damping force. In this case, the damping valve 43 is attached to the bearing case 42 side with the guide 37 side as the seat portion 44 . The bearing case 42 is provided with a dial 45 for rotating the bearing case, and a dial 45 is provided on the outer periphery of the guide 37 in the circumferential direction as a stopper to restrict the rotation of the dial 45 to intermittent rotation at every predetermined angle (1 pitch). A plurality of protrusions 46 are formed at equal intervals, and a leaf spring 47 that engages with these protrusions 46 is provided on the inner periphery of the dial 45.

On the outer periphery of the eye bracket 52 (which closes one end of the rod hollow part 32A) provided on the protruding end of the piston rod 32, there is a lubricating valve 53 for filling hydraulic oil, and on the outer periphery of the cylinder bottom wall 51 there is also an air bleed valve. 54 is attached. The oil supply valve 53 communicates with the rod hollow part 32A through a passage 55 of the eye bracket 52, and a passage 56 (shaft hole) is formed in the connecting rod 50, which communicates the rod hollow part 32A with the oil chamber B on the opposite side. Ru. Also,
The air bleed valve 54 is connected to the passage 5 in the cylinder bottom wall 51.
It communicates with the oil reservoir chamber C side via 7. Note that 58 indicates an eye bracket provided outside the cylinder bottom wall 51 so that a pillow 58A is located on the cylinder axis l.

During the extension stroke in which the piston 31 is displaced to the left in the figure and the oil chamber A contracts, the hydraulic oil in the oil chamber A opens the damping valve 43 and flows into the oil sump chamber C, while the hydraulic oil flows into the expanding oil chamber B. The oil corresponding to the volume of piston movement is supplied from the oil reservoir chamber C through the check valve 39. In addition, during the pressure stroke in which the oil chamber B contracts, the hydraulic oil in the oil chamber B flows through the check valve 35 to the oil chamber A as the piston 31 displaces, and excess oil (increased volume of the piston rod 32) flows into the oil chamber A. hydraulic oil) flows into the oil reservoir chamber C through the damping valve 43. In other words, during both expansion strokes, the oil in the cylinder 30 always flows in one direction, and the damping valve 43 opens and flows into the oil reservoir chamber C. The damping valve 43 provides resistance to the flow of this pressure oil, producing a damping force. to occur. In this case, piston rod 3
2 is formed by a hollow pipe, and a rod hollow part 34A is formed.
Since the piston 31 is opened into the oil chamber B, the pressure receiving area of the piston 31 is almost equal in both the expansion strokes, and the oil amount fluctuation due to changes in the penetrating volume of the piston rod 32 is also caused by the oil reservoir chamber C (expansion and contraction action of the outer shell 38). Since this is compensated, there will not be a large difference in damping force between the expansion and compression strokes. In addition, when adjusting the damping force, it is sufficient to rotate the dial 45 one pitch at a time.
The seat portion 4 of the damping valve 43 moves forward and backward along the
Adjust the initial load to 4.

By the way, when filling the damper 46 with hydraulic oil, first open the oil filling valve 53 and the air bleed valve 54, move the piston 31 to the position where the oil chamber B is expanded to the maximum, and in this state, open the oil filling valve 53.
The supply of hydraulic oil to the rod hollow part 32A starts from then. When the oil chamber B is almost filled with hydraulic oil, the piston 31 is moved to the pressure side while continuing to supply hydraulic oil, and the oil in the oil chamber B is transferred to the oil chamber A via the check valve 35, and then the damping valve 43 is moved. It is forcibly sent to the oil sump chamber C through the oil tank. Then, by periodically extending the piston 31 while feeding hydraulic oil, the oil is spread over almost the entire damper 45, and when the oil comes out from the air bleed valve 45,
The air bleed valve 54 is closed when the piston 31 is operated on the compression side and opened when the piston 31 is operated on the rebound side, so that the oil coming out from the air bleed valve 54 does not turn cloudy. In other words, hydraulic oil continues to be fed until the oil no longer contains air. In addition, the lubrication valve 53,
It is assumed that the air vent valve 54 is closed when the filling of the hydraulic oil is completed.

In this way, even without submerged assembly,
Hydraulic oil can be efficiently filled without allowing air to enter the damper 45.

Furthermore, since this steering damper 20 is a single-rod type in which the piston rod 32 protrudes only from one side of the cylinder 30, when used as a steering damper for a two-wheeled vehicle, for example, the mounting position on the cylinder 30 side (the position of the pillow 58A) is set to the piston rod 22 side. Similarly, by placing it on the axis l, that is, in the center of the bottom of the cylinder, the piston rod 32
It becomes possible to install the device in a state where almost no bending moment acts on the device, etc., and there is also the advantage that the installation space can be reduced due to the reduction in the longitudinal dimension.

(Effect of the invention) In summary, according to the present invention, a piston is slidably housed in a cylinder, oil chambers are defined on both sides of the piston, and a piston rod made of a hollow pipe is slidably housed at one end of the cylinder. The piston is supported freely and the oil chambers on both sides of the piston are connected via a check valve that prevents the backflow of hydraulic oil from the oil chamber on the piston rod side to the oil chamber on the opposite side. An oil sump chamber is provided to compensate for fluctuations in oil amount due to such factors, and a damping force is generated by applying resistance to the hydraulic oil flowing into the oil sump chamber through a passage that communicates this oil sump chamber with the oil chamber on the piston rod side. A force generating means is provided, and a check valve for preventing backflow of hydraulic oil to the oil reservoir is installed in the passage communicating with the oil reservoir and the oil chamber on the opposite side, and a hollow portion is provided at the protruding end of the piston rod. A lubricating valve for filling the hydraulic oil is connected to the oil chamber on the opposite side through the cylinder, and an air bleed valve is also installed on the bottom wall of the cylinder that communicates to the oil reservoir side.Although it is a single rod type, damping during both expansion strokes is achieved. By preventing differences in force from occurring, it is possible to install the piston rod in a state where almost no bending moment is applied, improving the reliability of the device.
In addition to improving durability and reducing the size of the mounting base, it is possible to efficiently fill hydraulic oil using an oil filling valve and an air bleed valve without submerged assembly.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of the structure showing an embodiment of this invention.
FIG. 2 is a configuration diagram showing the prior art, and FIG. 3 is a diagram showing its installation state. 30...Cylinder, 31...Piston, 32...
... Piston rod, 32A ... Rod hollow part, 3
3... Bearing, 35, 39... Check valve, 43
... Damping valve, 34, 40, 41 ... Passage, 5
3...Lubrication valve, 54...Air bleed valve,
A, B...oil room, C...oil sump room.

Claims (1)

[Scope of utility model registration request] A piston is slidably housed in a cylinder to define oil chambers on both sides of the piston, a piston rod made of a hollow pipe is slidably supported at one end of the cylinder, and the oil chambers on both sides of the piston are placed on the piston rod side. It is connected via a check valve that prevents the backflow of hydraulic oil from the oil chamber on the opposite side to the oil chamber on the opposite side, and an oil sump chamber is provided on the outer periphery of the cylinder to compensate for oil volume fluctuations caused by changes in the volume of the piston rod. A damping force generating means is provided in the passage connecting the oil sump chamber and the oil chamber on the piston rod side, which throttles the hydraulic oil flowing into the oil sump chamber to provide resistance and generate a damping force. A check valve is installed in the passage that communicates the oil chamber to prevent the backflow of hydraulic oil to the oil reservoir chamber, while a hydraulic oil is filled in the protruding end of the piston rod to communicate with the oil chamber on the opposite side through a hollow part. A steering damper characterized by having an air bleed valve connected to the oil reservoir chamber on the bottom wall of the cylinder.